This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Our lab in interested in methyl marks as modulators of protein and nucleic acid function. In the context of nucleosomes, we are interested in activity, regulation and chemical inhibition of histone demethylases, key enzymes involved in regulation of transcription. Additionally, we are investigating role of methylation of ribosomal RNA in translation. For success of these projects, it is crucial to accurately measure molecular weight of substrate macromolecules, and identify, via analysis of fragmentation patterns, exact sites of modification. Thus, these projects can not be accomplished without key inputs from mass spectrometry.